Convert Binary String to Integer Without strtol function or Libraries

Code

#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include<string.h>
uint16_t binary_to_uint(const char *str) {
    // Your logic here
    int n = strlen(str);
    int num = 0;
    int j = 0;
    for(int i=n-1;i>=0;i--){
        num += (pow(2,j)*(str[i]-'0'));
        j++;
    } 
    return num;
}

int main() {
    char bin[20];
    scanf("%s", bin);

    printf("%u", binary_to_uint(bin));
    return 0;
}

Solving Approach